I don't know you but, before I answer your question! I need to know what ship your goung on or the cruise line. But I'll try to help you even though I have no idea? But ooh well! Ok usually on formal nights ( well at least on the cruises I been on) girls ( 13 or whatever) ( im 13) yeah. I usually see us ( 13) not wearing to formal, I usally just see them wearing a black skirt and a black nice top and a sweater, but I saw girls about 16 they were really dressed up! ( woah!) they were wearing their prom dresses and stuff!
:-D Have FUN!

Hi i'm 13 and I've been on enough cruises to tell you that the majority of the ship does participate with formal gowns and prom dresses, but some people just wear skirts and a nice top. so whatever u wear it will be o.k. : )

when i went on my first cruise i was 13 and i wore a gown...but you can basically wear whatever you want. im going on my 3rd cruise in 3 days and on the second one..i didnt even participate in the formal night. I go off without my parents. Have fun!!